Technical Field
The present disclosure relates to a display device having touch sensors embedded in a pixel array.
Discussion of the Related Art
A user interface (UI) enables communication between a person (user) and various electrical and electronic devices such that the user can easily control the devices. Examples of the user interface include a keypad, a keyboard, a mouse, an on-screen display (OSD), a remote controller having an infrared or radio frequency (RF) communication function and the like. The user interface is developed to satisfy user emotion and to improve operation convenience. Recently, the user interface has evolved into a touch UI, speech recognition UI, three dimensional (3D) UI and the like.
The touch UI is included in mobile information devices such as smartphones and extended and applied to notebook computers, computer monitors, home appliances and the like. A technique (referred to as “in-cell touch sensor” hereinafter) of embedding touch sensors in a pixel array of a display panel has recently been proposed. The in-cell touch sensor enables installation of touch sensors in the display panel without increasing the thickness of the display panel.
The in-cell touch sensor uses electrodes connected to pixels as sensor electrodes C1 to C4 as shown in FIG. 1. For example, the in-cell touch sensor can divide a common electrode COM for supplying a common voltage Vcom to pixels of a liquid crystal display (LCD) and use the divided common electrodes as sensor electrodes of touch sensors, as shown in FIG. 1. Sensor interconnection lines W are connected to the sensor electrodes. The common voltage Vcom and a touch drive signal Tdrv are supplied to the common electrodes COM through the sensor interconnection lines.
When the sensor interconnection lines are embedded in a pixel array, the sensor interconnection lines are electrically coupled to pixel electrodes or signal lines. Accordingly, images may not be displayed in distinct colors on the display panel.
The display panel may have spacers provided therein. The spacers are formed between an upper substrate and a lower substrate of the LCD to maintain a cell gap of a liquid crystal layer. The spacers may be provided on the sensor interconnection lines W. In this case, an alignment layer may be raised by the thickness of the sensor interconnection lines W and thus the alignment layer may come into contact with the spacers. When the spacers come into contact with the alignment layer, particles may be generated due to friction between the spacers and the alignment layer. This causes bright point defects or hot pixels.